In order to achieve high efficiency and low damaged layers during a sapphire crystal lapping process,an experimental research on the rougness, lapping uniformity and sub-surface damaged layer were studied in this paper.The sapphire with (0001) orientation was lapped by 280 mesh boron carbide abrasive grits.The effects of lapping time on the material removal rates and surface roughness were investigated, and the processing remainders by the dual-lapping were determined in accordance with the surface states of the sapphire.Then micro-surface uniformity of the sapphire was also presented by using WYKO laser equipment. Finally,a nano-indentation test was carried out to measure the depth of damaged layer according to the hardness or modulus variances. Experimental results show that the sapphire crystal can offer the Ra in 0.523 μm,Rt<6.0 μm, the depth of heavy damaged layer of 460 nm,and the depth of sub-surface damaged layer no more than 1 μm, after it is lapped by the abrasive with 280 mesh boron carbide grits in 120 min.